While the communist party of India (marxist) , is not in power as of now , they have had history of winning elections, however there is a fatal flaw in their ideology , when it comes to fighting against opperession , while they agree upon existence of class disparity and want to work on the goal of removing it , the oldschool communists do not recognise caste system. For those who are not aware , caste system is a problem specific to indian subcontinent , it is like a dominant class of people who are called the upper castes ( tho in minority) , had deprived the lower castes , into not allowing them to get educated or get any other work that they were assigned at birth , by the family name they were born in . That kept the lower castes poor and deprived for ages. The CPI(M) is mostly flooded with the upper caste and do not recognise this systemetic opperssion that has been in place since ages !